In prior art used in IBM's mainframe InterSyetem Channels (ISCs) and Integrated Cluster Bus (ICB) channels, there are only four message buffer sets and this makes queuing frames and packets a quite simple process. Additionally, because these prior design implemented in IBMs S/390 and z Series (trademarks of International Business Machines Corporation) systems use code in multiple data frame transfers, a first-come-first-served algorithm is sufficient. In IBM's newest z Series mainframes, the number of message buffer sets is increased from four to 32. With this much larger number of message buffer sets, the first-come-first-served algorithm becomes much more unfair leading to having some message buffer sets starved for service.
A scheduling mechanism is needed which provides a method useable in a system where multiple frames and packets are queued for transmission over a link and queued from a link for storing into main memory. Such a method has not been created before and is desireable for these IBM machines.